The present invention relates to a material feeding apparatus for conveying sheet materials or a continuous strip material from a coil, which have a relatively large width, into a working machine such as a press machine.
FIG. 10 shows a conventional apparatus for intermittently feeding a continuous strip material from a coil, which has a relatively large width, into a die set in a press machine or the like. This is a roll feed system in which rolls 201, 202 having a large length are timingly driven by intermittent drive means 203, and a continuous strip material 204 is inserted between the two rolls 201, 202 and conveyed. As another conventional example, a sheet feeding system is shown in FIG. 11. In the sheet feeding system, dogs 305 (or fingers) for positioning sheet materials 304 are spacedly provided, at equal intervals, on a chain conveyer 303, and the chain conveyer 303 is intermittently operated by intermittent drive means 301 and sprockets 302, so as to deliver the sheet materials 304.
However, in the conventional feeding apparatus with the rolls of the large length, the shape and the strength of the long rolls make it difficult to adjust parallelism of the rolls; and a diameter of the rolls and the index number of the intermittent drive means must be changed to accurately control the feeding length. In consequence, the apparatus is increased in size and restricts the working space on the front side of the die, so that it is difficult to make access to the die for maintenance. Also, the conventional chain-conveyer type feeding apparatus occupies even more space than the roll feed system, and the die maintenance is more difficult. Further, since the dogs are employed, high-speed conveyance can not be achieved. Similarly, when fingers are employed, the conveyance speed is limited. Thus, exactly synchronized operation can not be effected. There coherently arises a problem that the material is easily damaged by the dogs or fingers.
This invention has been achieved to solve the above-described conventional problems. It is an object of the invention to provide a material feeding apparatus which can intermittently feed a material having a relatively large width at high speed, whereby adjustment of the apparatus and the die maintenance can be readily performed, and the material will not be easily damaged.